Cream Testing. 83 



Approximately correct results may be obtained in 

 testing thin cream by using an 18 cc. measuring pipette ; 

 to avoid the 'expense and trouble of using two different 

 pipettes, one for milk and one for cream, a pipette with 

 two marks on the stem, at 17.6 cc. and 18 cc., has been 

 placed on the market, the former mark being used when 

 milk is tested, and the latter for cream. It should be 

 borne in mind, however, that such pipettes can only be 

 used with fairly satisfactiry results in the case of sweet 

 cream of average richness. 



93. Use of milk test bottles. Cream may be tested 

 by emptying a 17.6 cc. pipetteful of the sample into 

 two or more milk test bottles, dividing the amount about 

 equally between the bottles and filling the pipette with 

 water once or twice, which is then in turn divided about 

 equally between the test bottles ; the per cent, of fat in 

 the cream is found by adding the readings obtained in 

 each of the bottles. The cream and the water must be 

 mixed "before the acid is added. 



This method does away with the error incident to the 

 adhesion of cream to the side of the pipette, but not 

 with that due to the low specific gravity of the cream, 

 and the results obtained will therefore be too low. The 



are measured out by means of a 17.6 cc. pipette. This increases the fluid- 

 ity of the cream and causes less to adhere to the pipette. The Vermont 

 experiment station found in examining this method that it did not 

 yield satisfactory results in the case of cream of different richness 

 and recommends that cream be weighed when accurate tests are de- 

 sired. (See report 16, pp. 191-6.) 



Professor Spillman, in Bull. 32 of Washington experimentlstation, 

 recommends the use of a 17.6 cc. pipette for testing cream, the results, 

 obtained being corrected by a certain per cent., as show r n in a table 

 given in the bulletin. The table is based on the figures given on p. 77 

 of this book, and is therefore only applicable to' fresh separator cream. 



